Lens surfacing machine



Ammwm CQPY J. J. M CABE ETAL 2,268,159 LENS SURFACING MACHINE Dec. 30,1941.

Filed March 27, 1941 v 4 Shets-Sheet 1 JOSEPH J. McCABE GEORGE C SCHELLING INVENTORS BY fig,

ATTORNEYS J. J. M CABE ETAL LENS SURFAGING MACHINE Dec. 30, 1941.

Filed March 27, 1941 4 Sheets-Sheet 2 JOSEPH J. Mc. CABE GEORGEC.SCHELL.|NG INVENTORS @TTORNEYS? 30,1941. J, MoCA BE EI'AL "2,268,159

mus suamcme mourns Filed March 27, 1941 4 sheets-sheets Fla:

JOSEPH J. McCABE' GEORGE C.SCHELLING INVENTORS ATToR'NE Dec.30, 1941.

J. J. MCCABE ETAL 2,268,159

LENS SURFACING MACHINE Filed March 2'7, 1941 4 Sheets- Sheet 4 as JOSEPHJ. M; CABE GEORGE c. SCH ELLING INVENTORS ,6 ATTORNE mini can 30,]19415r Joseph. J. McCabe,

Sohelling,

N. Ya,

Rochester, and George C. lrondequoit; Bausch azvLomb' Optical N. Y.,assignors to Company, Rochester,

a corporation of New York Application March27,1941,Serial No. 385,472

' :11 Claims. (01. 51-131) The, invention relates to lens surfacing.machines and more; especially is concerned with that type of machinewhereinv a reciprocating headisusedto:reciprocatea lens over a.rotatinglapa I I Anvimpor-tant.objectiof the invention is the provision,of: a. machineof" this character which utilizesrnechanica'l means toreciprocate a lens overwaqrotatingslap with armovement whichsimulates'that given aslensby arr-operator of a hand surfacing machinewhilemanually reciprocating the pressure handle" thereof. to surface alens.

Another object. of the .inventionresides in providing adjustableeccentric means for controlling the reciprocating movement of the 1polishing head of a,lens-surfacingvmachine wherein the stroke thereof isdetermined by, the position of an adjustable ball: havinga drive studformed thereon; r

The inventionshas as another'objectthe provisionofjanoveli mountingmeanspermitting the polishing head of awlens surfacing machine to beangledin; a vertical plane .located transversely of 1 the machine; and to be"adjustably positioned 'aboutran axis movable-in that plane as wellasthe provision: ofmeans for varying the positionof an arm carried bythepolishing head for supportingwork-engaging means; i

AIurther object oftheinvention is to provide a. lens surfacing: machinehaving gear means adapted tooperateawlever systemfor loweringandir'aising the polishing head of a machine into and out ofoperatinguposition together with means formaintaining work engagingmeans carried by the headin adjustable pressure contical effect withoutlimiting the improvements in their useful applications to the particularconstructions which, for the purpose of explanation, have been made thesubject of illustration. To this end the invention is disclosed in thefollowing manner, wherein:

Figure 1 is a perspective view of our lenssurfacing machine taken from aside thereof.

Figure 2 is a perspective view of the lens surfacing machine taken fromthe front thereof. 7 Figure 3 is a longitudinal vertical section of themachine with certain parts thereof removed. Figure 4 is a transversevertical section of the machine with certain parts thereof removed.

There is shown in Figure 1, like reference characters being usedthroughout the drawings to designate like parts, a machine engaged insurfacing a lens having a spherical surface. It will be appreciated,however, that through the use of suitable attachments our machine may beadapted to the polishing of cylindrical surfaces.

The machine comprises a hollow base 20 having tact with" a'lensblockrbyaconstruc'tion designed" to leave the pressure; adjustment unaffected bythe-actuation of the head: raising and lowering I means; a

Yet; a further object of the' invention is to provide a lens:surfacingjmachine of a simple design which maybe readilyrjembodiedrable and: eflicient structure;

in w a strong, du-

With. these and other objects in view which may be incidentltooursimprovements, the inven.

tion consists inthe partsand combinations to be hereinafter set forthand claimed, with the understandingthat the. 1 several necessaryelements comprising" our; invention maybe varied in construction,proportion and arrangement? without departing from-the spirit of 'theinvention orexceeding the, scope of the appended claims.

In order to makeour invention more clearly understood,z we have :shownin: the accompanying drawings-means for carryingcthe same into praca top2| and bottom 22 which latter members are provided with pairs of alignedbearings 23 within which are journaled the vertical work spindle 2i,intermediate shaft 25 and stroke control shaft 26. The function of theshafts 25 and 26 will presently appear. Suitable bearing covers 21,secured to the top and bottom of the base, are provided for the bearings23. Also journaled in the base in suitable bearings (not shown) is ahorizontal drive shaft 28 one end of which extends beyond the base andis provided with a drive pulley 29 around which is a guard 30 carriedfrom the base. A spiral gear 3| and worm 32, the latter shown in dottedlines in Figure 3, are fixed to the drive shaft 28. Gear 3| meshes witha spiral gear 33 fixed to the work spindle while the worm 32 cooperateswith a worm 34 fixed on the intermediate shaft 25, these means beingemployed to drive the work spindle and the intermediate shaft.

Foroperation, the machine is adapted to be placed upon a table or standwhich carries an electric motor connected by any conventional drivemeans, for example a belt, to the drive ventional grinding or polishinglap 31 best shown in Figure 1. Use is made of the usual fan 38 fixed tothe work spindle 24 above the top of the base in machines of this natureto prevent abrasive from entering the bearings of the apparatus. As bestnoted in Figures 2 and 3, lugs 39 are formed upon the top of the basefor detachably engaging the ribs or flanges on the exterior of aconventional splash pan 40 which surrounds thespindle during operationof .the machine. A suitable opening bottom of the pan 40 to' permit itto be placed is formed in the over the work spindle and to be seatedupon the' base top 2| of the machine.

Cooperating with the work spindle and lap is a hollow polishing head 4|which functions to.

maintain a lens on the lap in pressure engagement therewith and to causethe lens to be moved back and forth over the lap with a suitablegrinding motion. To this end the polishing head 4| is mounted above thebase by a construction which makes use of the spaced apart standards 42and 42 located on the top 2| transversely of the machine. A supportmember 43 is mounted I between the standards 42 by means of pivot screws44 to pivot about a horizontal axis which is parallel to thelongitudinal axis of the base 28 and which intersects the axis ofrotation of the work spindle 24. It is to be noted that the pivot axisof the support member 43 is horizontally arranged and is located abovethe top 2| of the machine base so that it is substantially tangentto-the center of a lap 31.

The support member 43 15 provided with an extension having a worm gearsegment 45 formed thereon for engagement with a worm 46 fixed on a shaft41 located at right angles to the pivots 44 and carried in shaftbearings 48 provided on the standard 42'. It will be apparent thatproper rotation of the operating handle 49 fixed on the shaft 41 willcause the support member 43 to be rocked or tilted about its pivots 44and angled as desired-in a vertical plane located transversely of thebase of the machine. If desired, suitable clamping means may beassociated with the structure just described to assure the maintenanceof the support member in adjusted positions.

As may be observed in Figure 3 the support member 43 is formed with abore which is provided with bearings 58 for rotatably mounting thesupport shaft 5| which is carried by the support member and which inturn carriesmhe polishing head, suitable bearing covers 52 beingemployed with this mounting. The shaft 5| ex tends above the supportmember 43 and is adapted to have a head support member 53 looselymounted thereon between a nut 54 which engages a threaded portion on theshaft located above theshaft support 43 and a nut .55 which engages theupper end of the shaft. Thrust washers 56 are placed between each nutand the end of the head support 53 adjacent thereto. Means for lockingthe head support 53 in adjusted position on the support shaft 5|comprises a clamp screw 51 which extends through a threaded bore in thewall of the head support and is adapted to engage the support shaft 5|,an operating handle 58 being provided on the clamp screw to facilitatethis adjustment.

Head support 53 is the member of the support structure to which thepolishing head 4| is directly connected and for this purpose is formedwith a projection .or support bracket 59. The polishing head ispositioned to surround the end means not only permitswear adjustment butalso provides a centering adjustment for the head with respect to theaxis of shaft 5|.

As previously noted, the polishing head 4| supports work engaging means.Use is made of an arm 6|, held within a bore in a projection on the head4| by a clamp screw 62 for slidable and rotatable adjustment withrespect to the work spindle, to permit adjustment of work engaging meansadapted to be carried on this arm.

A well known manually operated clamp 63 is.

fixed on arm 6| and is adapted to support a conventional type ofpressure pin, for example the resilient pin 64, in adjustablerelation'to the work spindle. The pin 64, as illustrated in Figure 1, isadapted to contact a lens block 65 having a blocked lens 66 and holdthis workag'ainst the lap. I

In lens surfacing machines it is necessary to keep the work in pressurecontact with the lap and it is desirable to provide positive means formoving the polishing head into operating and inoperative positions andfor locking the head in these positions. The mechanism for raising andlowering the head 4| out of and into a work position is shown in detailin Figures 3 and 4 and comprises a gear train which drives an eccentricconnected to a lever system with which is associated spring means forapplying pressure to the polishing head. To this end the head support53, which is usually cast, is provided with a gear box 61 having asuitable cover 68 secured thereto. Gear shafts 68 and 10 are journaledin the gear box and are respectively provided with the drive pinion 1|and driving gear 12 which are in mesh with each other and which arefixed to their respective shafts. The shaft 68 extends through the cover68 and has a suitable crank 13 secured to its end while the'shaft 10extends through the opposite side of the gear box and has its end underthe polishing head 4| provided with an eccentric 14.

Pivotally secured upon the eccentric 14 is a bifurcated raising link 15which is provided with an adjustable stop 16. A lever 1/1, is positionedbetween the forked ends of the {raising link 15 and is pivotedtheretob'y a pivot pin 18 which extends through the raising link and toone side thereof, this lever in turn' having one end mounted on a pivotpin 19 held between spaced lugs formed on the head support member 53 adpressure arm 83 mounted ona pivot 84 located within the head 4|. One endof the pressure arm 83 is provided with a threaded post 85 to which issecured one end of a spring 86, a similar thespring. A contact member 61isformedat the end: of the pressure arm away from the spring for contactwith the end of a slldable pressure pin 60 carried ina guideway formedin the top of the polishing head. This guideway It is threaded at itsouter end to receive a pressure screw 60 operated by a hand wheel ii toengage the end of the pressure pin 86 withinthe guideway and to adjustthe tension of the spring 06.

In Figures .1 and 3 the pressure head. if is shown in a lowered oroperating position. Where such is the case the eccentric I4 is offcenter with the result that it is out of alignment with pivot pin I6and-lifting pin 82 as illustrated'in Figure 3. Or toLput it another way,the axis of the. eccentric M is offset from. a plane which passesthrough the axis of pin 62. and the pivot "for the link 15, lever "andarm 0|. Also when the pressure head is lowered and the pressure pin 6|is engaged with a lens block, the stop I6 is in contact with the bracket50 and the 01 against their respective fixedly positioned bracket 56 andpressure pin 66, the force of the spring is limited to moving thepressure head downwardly or in a counterclockwise direction I about itspivot 60. This prov-ides the necessary pressure contact between the workand the lap and may obviously be decreased or increased at any time bysuitable operation of the hand When the raising link 15 and stop 16 are10- cated as shown in Figure 3 and the resilient pin expedient assuresmaintenance of grinding con-, tact during surfacing operations.Obviously adjustment of the stop 16 permits any desired variation forthe operating off centered position of the eccentric I4. At the sametime it may be noted that actuation of the hand wheel 01 allowsvariation of the grinding pressure either during operation of the deviceor while it is at rest.

The ratio between the gears Ii and 12 is so selected that the stroke ofthe handle for raising the polishing head will move the eccentric 14through an angle greater than 180 and position. the eccentric somewhatabove its location shown in Figure 3 but also in ofl'centered relationto the pivot 16 and lifting pin 02. This just described movement of theeccentric 'llcausesrthe raising link 15 to be moved in a clockwisemanner as viewed in Figure 3 about the gear. shaft 10 as a center. Firstlink 16 moves downwardly and to the left and thentupwardly, at first tothe leftand then to the right, until the stop I6 contacts the bracket50. g

The just] described movement of the link 15 will, of course, lift boththe lever 11 and arm 6b to which the link is pinned. This results in thespring 66 being allowed to contract and in the arm 64 fully engaging thepin 02 and raising the polishing head Ii about its pivot to theinoperative position iliustrated in Figure 2. It will be apparent thatwhen the polishing head is in its raised and inoperative position thatthe oil centered location of the eccentric I4 will effectively preventits downward movement under its own weight and that it will be safelylocked in this position. A small amount of play has been shown in Figure3 between the lifting arm BI and its pin 82 when the polishing head isin operating position. This play has been provided to permit slightmovement of the polishing head aboutits pivot 59 during operation of themachine in order to care for the curvature of the lens being surfaced.

Obviously movement of the crank 13 in a reverse direction from thatdescribed will lower the polishing head from its inoperative position tothe surfacing position of Figures 1 and 3 and will cause the eccentricl4 and link 15 to move in a counterclockwise direction into theoperating position heretofore described. In this downward movement ofthe polishing head the spring 06 will remain contracted until theresilient pin 64 contacts its lens block. Upon continued op-: eration ofcrank 13 for its lowering stroke, the polishing head and arm 83 willremain substantially stationary relative to the eccentric H and lever 11so that the movement of the latter will expandthe spring 86 and place itunder the tension necessary to create a grinding pressure between thelens and the lap.

In surfacing operations it frequently becomes necessary to remove a lensfrom the lap for inspection. When such is the case it is highlydesirable to resume surfacing under the same grinding.pressure. It willbe apparent that the structure disclosed permits the head tobe raisedand lowered without affecting the pressure adjustment so that anoperator of the machine is assured that the polishing head will developa substantially constant operating pressure for each setting of the handwheel 9|.

The polishing head and the work engaging means have been described asadapted for re ciprocation over the lap of the machine. In accomplishingthis it is necessary to reciprocate the support shaft 5| with the headlocked thereto. To this end, power is taken off the intermediate shaft25 to drive the stroke control shaft 26 which is coupled to the supportshaft 5 i. As best shown in Figure 4, a drive spur gear 92 is fixed tothe intermediate shaft 25 to mesh with a driven spur gear 03 fixed onthe stroke control shaft 26. Under these conditions it will be apparentthat the stroke control shaft 26 will be rotated upon actuation ofthedrive shaft 28.

The stroke control shaft 26 textendsabove the top 2! of the base of themachine and has the lower part 04 of a divided ball housing 05 fixed toits free end to rotate therewith, the upper part 96 of the ball housingbeing secured to the lower part by means of suitable fastenings 81. Asmay be observed in Figure 4, the interior of the ball housing 05isprovided with an opening which extends therethrough and whose axis isnormal to the shaft 26. This opening has outer portions which are in theform of slots 98 while its central portion is recessed to form a socketfor a ball 98 having drive pins I00 extending therefrom and engagedwithin the slots 88. Also projecting from ball 00 is a drive stud i0lwhich extends through an opening I02 provided in the upper member 96 *ofthe ball housing and for some distance above the same.

The height of the slots 98 is considerably greater than the diameter pfthe drive pins I00 v with the housing 95 and the shaft 26.

while the width of the slots is substantially equal to that of the drivepins. Through this expedient the ball 99 and its stud IOI are caused torotate At the same time this construction permits adjustment of the ball99 within its recess whereby the drive stud IOI may be moved into aposition'out of alignment with the longitudinal axis of the shaft 26.Obviously the angular movement of the drive stud with respect to theshaft 26 is limited only by the size of the opening I02 and the heightof the slots 98.

The drive stud IOI serves as a crank, the throw or eccentricity of whichis adjustable at will. For the purpose of holding the drive stud inadjusted positions, a passageway is formedto extend through the drivestud IM and the ball 99. One end of this passageway is threaded toreceive a clamp screw I03 provided with a suitable operating knob I04.The opposite or ball end of this passageway is enlarged as shown inFigure 4 to receive a slidable pressure plug I05 adapted to be pressedagainst the bottom of the recess in the ball housing 95 to hold the balland the drive stud in adjusted position. As

may be noted, the head of the plug I05 is a spherical surface of thesame radius as the ball 99 so as to permit suitable contact with thesocket in the lower housing 94. v v

Slidable within the passageway in'the drive stud and ball is a pressurepin I06 which is 10- rated between the end of the clamp screw I03 andthe pressure plug I05. As the ball is retained within its socket byreason of the connection of the upper housing 96 to the lower housingv94, it will be apparent that sufficient movement of the clamp screw I03towards the ball 99 will force the pressure pin I06 against the pressureplug I05 to cause the latter to firmly hold the drive stud in anadjusted position.

The construction for coupling the drive stud to the support shaft makesuse of a sleeve or eccentric strap I01 loosely supported on a shoulderI08 formed on the drive stud and held thereon by the collar I09 fixed tothe stud by the set screw or other fastening IIl A connection link IIIhaving av yoke II2 pivoted to the eccentric strap I01 by pivot screwsIII is coupled to a reciprocating drive arm II4 which in turn is securedto the support shaft SI. Another yoke H is formed on the other end ofthe connection link III at a right angle to the yoke H2.

The face of yoke II5 adjacent the drive stud is provided with a. recesswhich supports a resilient connection plug IIB adapted to extend withinthe yoke. A second resilient connection plug II'I, aligned with the plugH6, is slidably carried in a passageway in the connection link III whichopens into the yoke and extends through the link to its outer end. PlugsH6 and II! pivotally connect the link III to a ball H8 formed on aconnection member suitably secured to the end of the reciprocating arm-I I4 by suitable fastening means II9. By means of the pressure screwI20 engaged in the threaded end of the support guideway for theresilient connection plug III, the plugs H6 and III and ball I I8 arepivotally connected to each other. A lock nut I2I is 'used with thescrew I20 to lock the same in engaged position. It is to be noted thatthe center of the ball II 0 lies in the axis of the pivot screws 44about which the support member 43 and support shaft 5I are adapted topivot.

As may be noted, the reciprocating drive arm I I4 bends upwardly fromthe ball connection I I8 and has its end opposite thereto provided witha connection collar I22iwhich loosely engages thepp rt shaft 5| and-issecuredttheretoby the. set screw I23 (Figure-l) or 1 othen'suitablefasten-s. ing means. This connectioni'c'ompletesthe "drive means forreciprocating the pressurehead'4Land its work engaging n'ieansl H Hand,surfacingmachineswhe'rein a lens is reciprocatcd by handover a rotatinglapp'ossess' certain advantages which it isde'sirable to simu-:

late. For example,'inhand'surfacingy the lens" 5 is readily located onany-portion ofth'e lap and is easily changed to other positions; Alsothe amount'of movement impartedto a lens over a lap is determined by theleng-th 'of the hand stroke of the operator; which'strokeis of course.

variable at the wilhof the operator.. In addition, hand surfacingai'nachine of the type just described is accompanied .by reciprocationof the lens along substantially continuously changing paths which are-very rarely repeated; I

At the same time-hand surfacing requires a separate operator forealchmachine so'that it is im possible for one person to operate a number'ofmachines. i

That our machine is capable ofcloselyretaining the advantages of a handsurfacer while overcoming its limitation will be apparent from lowered.3

Location of the pin 64' on either. side of th longitudinal axis of themachine'is readily efiected by tilting the polishing'head 4i aboutitspivots 44 through the mechanism driven: by the handwheel 49 and also bythe arcuate adjustment of the polishing head about the support shaft 5|as a center, thepolishing head being held in adjusted position on theshaftil by locking the head support member 53 to the shaft throughthe'clamp 51. Byadjusting the arm 6|, the resilient pin-maybe angledwith respect to its lap and also may-be positioned forwardly orrearwardly of a transverse axis of the machine which passes through thework spindle 24 while obviously the vertical position of r the pin willbe controlled by its locking location with respect to the clamp 63. Itwill be apparent that the foregoing adjustments permit a lens to belocated wherever desired upon its lap, which position may be shiftedwhenever necessary by suitable readjustment of pin 04; 1

The polishing headis'now lowered until the resilient pin engagesthe-lens block after which the full stroke of the crank 13 is completedto lock the head in operating 'position'and to en gage the resilient pinin pressurecontact with the lens block. This pressure iseasily'decreased or increased by operation of the hand wheelSI.Operation of the hand wheel I04'to set thethrow of the drive stud IOImay now 'be made. The amount of the stroke or the'movement of thepolishing head needed for surfacing will be dependent upon theparticular lens being surfaced and is readily understood by the art.Quite obviously the stroke of the polishing head may be changed iromitsinitial setting to some other adjustment at any time that the machine isat rest. a n r r 44 in line with the center of the lap 31.

A suitable abrasive is placed upon the lap and the switch handle 35 isturned to cause actuation of the drive shaft 28 and rotation of the workspindle and lap and reciprocation of the polishing head and its Workengaging means. It is apparent that when'the axis of the drive stud I!is moved out of alignment with the axis of the shaft 26 that the drivestud functions as an eccentric or crank which will reciprocate the linkHI and arm H4 so as to cause reciprocation of the polishing head of themachine.

The reciprocating stroke or movement of the polishing head will varyfrom zero when the drive stud lDl and shaft 26 are aligned to a minimumfor the maximum angular setting of the drive stud with respect to theshaft 26. It will be apparent that by reason of the adjustable ballconnection of the drive stud ID! to the shaft 26 that the throw of thedrive stud is susceptible to minute or large variations over arelatively wide range. These means permit a stroke variation for thework engaging means which is comparable with that-obtained in a handsurfacing quickly made without disturbing the work or any of the otheradjustable parts of the machine.

The friction existing between the lens and the rotated lap will causethe former to be rotated. At the same time the lens and lens block arereciprocated over the lap at a frequency which differs from therotational frequency of the lap. As will be well understood thecombination of these movements will cause the lens to bereciprocated'over the lap so that it will follow the same path ofmovement only at infrequent intervals.

An important feature of our machine resides in the construction whichlocates the pivot axis For this reason tilting of the polishing head onthis axis not only permits the resilient pin 64 to be located on eitherside of the lap but will also allow the lens to be reciprocated over thelap in a manner to compensate for the curvature of the latter. Thetilting of the polishing head is especially designed to maintainmovement of the lens along paths which are approximately tangential tothe lap surface. Obviously the angle of tilt required for the polishinghead will in-- crease with the radius of curvature of the lens beingsurfaced.

.Where it is found necessary, any of the adjustinents noted may beeasily remade in the manner described upon stopping the actuation of themachine. Frequently, as previously mentioned, it is desirable to removea lens from the lap for inspection. This is carried out by stoppingthedevice and swinging the crank I3 for the full extent of it raisingstroketo raise the polishing head to the position shown in Figure 2where it is automatically, locked against accidental lowering movement.After the lens block has been replaced on the lap. the crank .l3 may beturned in the proper direction to again lower'the polishing head intooperating position and the surfacing operation may be resumed, it beingnoted that the pressure adjustnientduring the raising and relowering ofthe polishing headhas remained at a constant setwe have provided a lenssurfacing machine of simple design and rugged construction which issusceptible of facile operation. At the same time in attaining ourinventive aims, we have devised a novel machine which simulates handsurfacing procedure but greatly accelerates surfacing operations whilemaintaining a fine control ove them.

We claim:

1. A lens surfacing machine having a base, a

drive shaft journaleo therein, a Work spindle and an intermediate shaftalso journaled therein and driven from said driveshaft, a stroke controlshaft journaled in the base and driven from said intermediate shaft, arotatable support shaft carried on said base, a polishing head securedto said support shaft, work engaging means carried by said head andmeans for reciprocating said head on actuation of said drive shaftcomprising a housing fixed to said control shaft, a ball having a drivestud thereon, said ball adjustably mounted within said housing to permitpositioning of the stud eccentric of said stroke control shaft and linkmembers drivingly connecting said stud and said polishing head supportshaft.

2. In a lens surfacing machine the combination of a base, a rotatablework spindle in said base, a polishing head secured to a rotatable shaftcarried on said base, drive means for said spindle and means forreciprocating said head, said reciprocating means comprising a strokecontrol shaft rotatably mounted in said base and actuated from saiddrive means, a housing secured to said control shaft, said housingprovided with a socket, a ball adjustable in said socket, a drive studon said ball, pins on said ball engaged by said housing, pressure meansfor-holding said ball in adjusted positions and link members operativelyconnecting said stud to said polishing head.

3. In a lens surfacing, machine the combination of a base, a rotatablework spindle therein, a polishing head secured .to a rotatable supportshaft carried by said base, drive means for said spindle and means forreciprocating said head comprising a rotatable stroke control shaftmounted in said base and actuated from said drive means, a housingsecured to an end of said stroke control shaft, said housing providedwith a socket, a ball retainable and movable in said socket, a drivestud projecting from said ball and beyond said housing, pins on saidball engaged by said housing, said stud and ball provided with anopening extending entirely therethrough, a clamping plug engageable withsaid housing mounted in the end of said bore adjacent the surface ofsaid ball, a pressure pin slidable in said bore and contacting saidplug, a threaded portion at the other end of said bore, a clamp screwengaging said threaded portion and contacting said pressure pin, andlink members operatively connecting said stud to said polishing headsupport shaft.

4. A lens surfacing machine comprising a base, a work spindle journaledtherein, a support shaft rotatably mounted upon said base, a polishinghead secured to said support shaft, work engaging means carried by saidhead, drive means for said spindle and means for reciprocating saidhead, said reciprocating means having a stroke control shaft journaledin said base and rotated from said drive means, a housing fixed to saidstroke control shaft, a ball having a drive stud projecting therefrom,said ball adjustably mounted within said housing to permit positioningof said stud eccentric of said stroke control shaft, pins on said ballengaged by said housing, a link member in the form of an arm having ayoke at each end thereof, a second link member having one end fixedlyengaged to said support shaft and its other end engaged in one of saidyokes, said stud extending through the other yoke and pivotallyconnected thereto.

5. A lens surfacing machine having a base, a drive shaft journaledtherein, a work spindle and an intermediate shaft also journaled thereinand driven from said drive shaft, a stroke control shaft journaled insaid base and driven from said intermediate shaft, a support shaftrotatably mounted above said base and angularly adjustable in a verticalplane located transversely of said base, a polishing head secured to thesupport shaft, work engaging means carried by said head, gear means forangularly positioning said support shaft, and means for reciprocatingsaid head on actuation of said drive shaft comprising a housing fixed tosaid control shaft, a ball having a drive stud thereon, said balladjustably mounted within said housing to permit the longitudinal axisof said stud to be positioned out of alignment with the longitudinal.axis of said stroke control shaft and link members operativelyconnecting said stud to said head support shaft.

6. A lens surfacing machine having a base, a drive shaft journaledtherein, a work spindle and an intermediate shaft also journaled thereinand driven from said drive shaft, a stroke control shaft journaled insaid base and driven from said intermediate shaft, a support shaftrotatably mounted above said base and angularly adjustable in a verticalplane located transversely of said base, a polishing head looselymounted on said support shaft, locking means for securing said head toits support shaft to rotate therewith, an extensible arm carried by saidhead, work engaging means carried by said arm, gear means for angularly4 positioning said support shaft, and means for reciprocating said headon actuation of said drive shaft comprising a housing fixed to saidcontrol shaft, a ball having a drive stud thereon, said ball adjustablymounted within said housing to permit the longitudinal axis of said studto be positioned out of alignment with the longitudinal axis of saidstroke control shaft and link members operatively connecting said studto said head support shaft.

'7. In a lens surfacing machine the combination of a base, a workspindle rotatably mounted in the base, a pair of standards extendingabove the base, a shaft support member pivotally mounted between saidstandards for tiltingmovement about a horizontal axis locatedlongttudinally of said base, gear means on said support membercooperating with gear means on said base for tilting said supportmember, a support shaft rotatably mounted within said support member, apolishing head secured to said support shaft, work engaging meanscarried by said head, drive means for said spindle and means forreciprocating said head, said reciprocating means comprising a strokecontrol shaft rotatably mounted in said base and actuated from saiddrive means, a housing secured to said control shaft, said housingprovided with a socket, a ball adjustable in said socket, a drive studon said ball, pressure means for holding said ball in adjustedpositions, pins on said ball engaged by said housing, and link membersoperatively connecting said stud to said polishing head.

8. In a lens surfacing machine of the type having a polishing headadapted to be reciprocated over a lap, said polishing head being pivotedfor movement into operative and inoperative positions, means for movingsaid head into said positions comprising a shaft rotatably carried bysaid head, an eccentric on said shaft, gear means for rotating saidshaft, a link pivoted to said eccentric, anarm pivoted to said link,said arm provided with a slot, a pin fixed to said head and engaged withsaid slot, said eccentric located out of alignment with the pivot centerof said arm and the center of said pin when the polishing head is inoperative and in inoperative positions.

9. In a lens surfacing machine of the type having a polishing headpivotally mounted and adapted to be raised and lowered into operativeand inoperative positions with respect to a lap mounted on said machineand to be reciprocated ever the lap to cause work engaging means carriedthereby to reciprocate a lens block and lens over said lap during theactuation of the machine, means for moving said head into said positionscomprising a shaft rotatably carried by the head, gear means forrotating said shaft, an eccentric on said shaft, a link having one endthereof pivoted to said eccentric, an arm having one of its ends pivotedto the other end of said link, the end of the arm opposite said pivotprovided with a slot, a pin on said head engaged with said slot, theaxis of said eccentric located in offset relation to a plane passingthrough the axis of said pin and the axis of the pivot for said link andarm when said head is in raised and lowered positions and stop meanscarried by said link for limiting the movement of said head about itspivot.

10. In a lens surfacing machine having a head support member and apolishing head pivoted thereto and adapted to be moved into operativeand inoperative positions with respect to a lap on said machine and tobe reciprocated over the lap during actuation of the machine to causework engaging means carried thereby to reciprocate a lens block and lensover said lap, the combination of means for moving said head into saidpositions and means for exerting a grindingpressure on a lens on the lapcomprising a shaft rotatably carried by said head, gear means forrotating the shaft, an eccentric on said shaft, a link pivoted on saideccentric, an arm pivoted to said link, said arm having a slot, a pinfixed to said head and engaged with said slot, a lever pivoted to saidhead support and also to said link about the pivot axis of said arm, apressure pin in said head, a second arm pivoted to said head and heldagainst said pressure pin by tension developed by a spring connectedthereto and to said lever, and stop means on said link contactable withsaid head support to limit the movement of said head. the axis of saideccentric offset with respect to a plane through the axes of said slotengaged pin and the pivot for said link and first mentioned arm whensaid head is in said positions.

lap on the spindle, a rotatable shaft on said base,

a polishing head support secured to said shaft, a polishing head, workengaging means carried by said head for contact with a lens block andlens on said lap, said head pivoted to said head support, rotatablecrank means for reciprocating said head, drive means for said spindleand said crank means, adjustable means for varying the by said arm. saidlever also pivoted to said head 10 support, adjustable spring tensionmeans connecting said lever to said head, and stop means on said linkcontactable with said head support, the axis of said eccentric locatedin offset relation to a plane through the axes of said pin and the pivotfor said link and arm when said head is in 0per ative and inoperativeposition.

JOSEPH J. MCCABE. GEORGE C. SCHELLING.

